1. Field of the Invention
The present invention relates to an optical element driving device that moves an optical element holder by slidingly moving a magnetic body by vibrating a magnet with a piezoelectric element. The present invention also relates to an optical element barrel and an image pickup apparatus including the optical element driving device.
2. Description of the Related Art
Image pickup apparatuses, such as digital still cameras, digital video cameras, and the like, focus an image of an object by using an image-taking optical lens (optical element). An image pickup device, such as a charge coupled device (CCD) image sensor or a complementary metal oxide semiconductor (CMOS) image sensor, is disposed to the rear of the optical lens, and the image pickup device forms the image of the object.
In order to prevent degradation of an image due to shaking of such an image pickup apparatus, some digital still cameras and digital video cameras include an optical motion blur correction mechanism. To be specific, motion blur of an image is corrected by moving the optical lens in two directions that are perpendicular to the optical axis. As an optical element driving device for moving an optical lens, for example, a technology using an electromagnetic actuator including a coil and a magnet is comparatively widely used.
As an actuator for moving an optical lens, technologies using a piezoelectric element have been disclosed. For example, a technology using a bimorph piezoelectric element in order to move a lens for motion blur correction has been disclosed. Another technology uses a stack of piezoelectric ceramic plates in order to increase displacement of a piezoelectric element.
Another technology enables a driving force generated by a piezoelectric element to be stably transmitted to an optical element holder by using magnetic attraction between a magnet that is attached to the piezoelectric element and a magnetic body that is attached to an optical element holder that holds an optical lens.